1. Technical Field
The preset invention relates to a guiding device, for an umbilical member including a cable and/or a tube of an industrial robot, and to a robot having the guiding device.
2. Description of the Related Art
When an industrial robot is used for an operation, the robot is required to be provided with an umbilical member including a cable and/or a tube for transmitting power or a signal to an end effector attached to the end of a wrist element of the robot. When the umbilical member is arranged around the wrist element of a robot arm, the umbilical member may contact the arm or another external equipment and may be worn or damaged. In order to avoid such an inconvenience, several configurations has been proposed.
For example, Japanese Unexamined Patent Publication No. 2001-150382 discloses a configuration in which a clamp arranged on a suitable site near a wrist element holds an umbilical member. The clamp is attached to a point of a rotation axis of an arm such that the clamp holding the umbilical member may be rotated relative to the wrist element. As the clamp is rotated according to the motion of each axis of the wrist element, the umbilical member is prevented from winding on to the arm.
Japanese Unexamined Patent Publication No. 2003-136462 discloses that an intermediate member having a two connecting members for connecting two flanges is arranged between a wrist flange and an end effector. The umbilical member extends through the intermediate members or between the two connecting members.
Further, Japanese Unexamined Patent Publication No. 7-124886 discloses a coupling member having an opening in the center thereof, through which the umbilical member may extend. The coupling member has a generally cylindrical shape and is arranged at a rotational joint of the robot for transmitting a rotary force. One end surface, and a side surface, of the coupling member have wide openings. The umbilical member is introduced into the coupling member from the opening of the side surface and led out from the opening of the end surface.
In the configuration disclosed in Japanese Unexamined Patent Publication No. 2001-150382 in which the clamp holds the umbilical member, the umbilical member, positioned near the clamp, does not contact the arm or the wrist of the robot. However, the umbilical member positioned at a place other than near the clamp may contact the arm or the wrist. Therefore, it is necessary to loosen the umbilical member between each clamp, with the result that the loosened umbilical member may contact the external equipment. Further, in order to avoid interference between each clamp when the wrist rotates, an operating range of the wrist must be limited.
In the configuration disclosed in Japanese Unexamined Patent Publication No. 2003-136462, the rigidity of the intermediate member is low because the connecting member of the intermediate member is divided into two parts. Therefore, the end effector vibrates when the robot is activated. In order to avoid the vibration, an operating speed of the robot must be restricted, resulting in a cycle time of the operation increasing.
Further, in the configuration disclosed in Japanese Unexamined Patent Publication No. 7-124886, in which the coupling member is arranged between the wrist flange and the end effector, the coupling member has an opening on generally the center of a surface of the coupling member fixed to the end effector. When the umbilical member is arranged through the coupling member, the umbilical member must be drawn from the center of the surface fixed to the end effector, resulting in the umbilical member interfering with the end effector.